Warnings during make check

[Florian Weimer]

* Christer Solskogen via Libc-alpha:

> Are these types of warnings OK to ignore or should they be fixed?
> Ubuntu 21.04 - gcc version 10.3.0 - binutils 2.36.1 - running "make
> check" on glibc master.

They all test functionality for which warnings are expected when used
outside of glibc.  I do not think there is a good way to suppress those
warnings.  We want to test the actual installed binaries as far as
possible.

Thanks,
Florian